Sensor band for multimodal sensing of biometric data

ABSTRACT

A resilient fabric band providing a sensor platform for a wearer in order to sense, a plurality of biometric data, the band comprising: a pair of ECG sensors coupled to an interior surface of a body of the band, each of the pair of ECG sensors located on either side of a front to back centerline of the body; a pair of bio impedance sensors coupled to the interior surface of the body of the band, each of the pair of bio impedance sensors located on either side of the front to back centerline; a strain gauge sensor coupled to the body of the band; a computer device mounted on the body of the band via a housing, the computer device including a power source, a computer processor, a memory for storing instructions for execution by the computer processor, and a network interface for transmitting data sensed by the sensors; and a plurality of communication pathways connecting the computer device to each of the sensors, the communication pathway for sending power from the power supply to the sensors as controlled by the computer processor and for receiving sensed data from the sensors by the computer processor.

FIELD

The present disclosure relates to sensing systems for biometric data.

BACKGROUND

Sensing of biometric data in today's technological based environment is key to understanding the physical state. In particular, athletes and medical patients, among a number of other consumers, are key individuals for much needed accurate and up-to-date (i.e. real-time) biometric sensing. However, state of the art sensor arrangements can be bulky and uncomfortable for the typical wearer. Further, each physical activity and/or health condition can require a customized sensor arrangement and mode of attachment to the wearer, which can unnecessarily require multiple sensor platforms tailored to each individual/disease.

SUMMARY

It is an object of the present invention to provide a biometric sensing platform to obviate or mitigate at least one of the above presented disadvantages.

An aspect provided is a resilient fabric band providing a sensor platform for a wearer in order to sense a plurality of biometric data, the band comprising: a pair of ECG sensors coupled to an interior surface of a body of the band, each of the pair of ECG sensors located on either side of a front to back centerline of the body; a pair of bio impedance sensors coupled to the interior surface of the body of the band, each of the pair of bio impedance sensors located on either side of the front to back centerline; a strain gauge sensor coupled to the body of the band; a computer device mounted on the body of the band via a housing, the computer device including a power source, a computer processor, a memory for storing instructions for execution by the computer processor, and a network interface for transmitting data sensed by the sensors; and a plurality of communication pathways connecting the computer device to each of the sensors, the communication pathway for sending power from the power supply to the sensors as controlled by the computer processor and for receiving sensed data from the sensors by the computer processor.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects will now be described by way of example only with reference to the attached drawings, in which:

FIG. 1 is a perspective view of a band containing a plurality of sensors;

FIG. 2 is a view of the band shown in FIG. 1 incorporated into an article of clothing;

FIG. 3 shows an embodiment of the band shown in FIG. 1 with associated electrical components;

FIG. 4 shows example applications of the biometric data combinations;

FIG. 5 shows a front perspective view of a further embodiment of the band of FIG. 1;

FIG. 6 shows a rear perspective view of the further embodiment of FIG. 5;

FIG. 7 shows a side view of the sensors mounted on the band of FIG. 5; and

FIGS. 8 and 9 show further embodiments of the sensors of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, shown is a fabric band 10, preferable having a resilient knit type, for fitting around a body part of a wearer (not shown), in order to collect different modes/types of biometric data based on the type/number of sensors 12 positioned either on or otherwise knit/woven (e.g. embroidered) into the fabric making up the body of the band 10. It is recognised that the body part can be such as but not limited to: waist or abdomen; limb such as a leg or arm; torso/trunk; buttocks; foot or ankle; wrist or hand; and/or head. The fabric band 10 can be provided as a stand-alone article or can be combined/combined into an article of clothing such as but not limited to: underwear 11 (see FIG. 2—such as but not limited to any type of undergarment including jockey shorts, panties, undershirts, and bras); socks, limb bands (e.g. knee band); shirt (e.g. undershirt); etc. In terms of combined into an article of clothing (i.e. garment 11), the band 10 can be formed as an integral component of the interlacing of the fibres making up the garment 11. The fabric of the body of the band 10 can be comprised of interlaced resilient fibres (e.g. stretchable natural and/or synthetic material and/or a combination of stretchable and non-stretchable materials).

Referring again to FIG. 1, provided as distributed about the band 10, e.g. mounted on an interior surface 111 (i.e. inward facing towards the body of the wearer), are a series of sensors/electrodes 12 including ECG sensors 12 a, bio impedance sensors 12 b, and strain gauge sensors 12 c. It is recognised that the sensors 12 can be composed of Electroactive polymers, or EAPs, and/or woven or knit plurality of conductive fibres constructed in a sensor/electrode configuration (e.g. a patch).

Also positioned on the band 10, for example on, an exterior surface 13 (i.e. outward facing from the wearer), is series of electrical components 15 including a computer device 14 (see FIG. 3) including a computer processor 16, a memory 18 for executing stored instructions for receiving and processing of data obtained from the sensors 12, as well as communicating via a network interface 20 with a network 22 (e.g. Wi-Fi, Bluetooth, attached wired cable, etc.) as well as sending and receiving electrical signals from the sensors 12. The processor 16, memory 18 and network interface 20 are mounted on a printed circuit board 26, which is housed in a housing 24 attached to the band 10. Also connected to the PCB 24 is a temperature sensor 12 d for measuring a body temperature of the wearer. Also mounted in the housing is a power supply 28 (e.g. battery) for powering the various electrical components 15 within the housing 24 as well as the sensors 12 a,b,c external to the housing 24, connected via conductive communication pathways 30 (e.g. wires—see FIG. 1—woven into the fabric weave/knit of the band 10 textile). The pathways 30 can be coupled to the sensors 12 via use of a conductive grommet, as desired. Also provided is a series of motion sensors 36 (e.g. accelerometer(s) and gyroscopes) for determining movements of the wearer, including posture as further described below. The sensors 12 can also be provided as speaker/microphone (e.g. for auditory signals/communication with the wearer), illumination sensors (e.g. LEDS—for visual signals/communication with the wearer) and haptic/vibrations sensors (e.g. actuators—for motion/touch signals/communication with the wearer),

Sensor Examples

The sensors 12 can be composed of Electroactive polymers, or EAPs, which are polymers that exhibit a change in size or shape when stimulated by an electric field. EAPS could also exhibit a change in electrical field if stimulated by mechanical deformation. The most common applications of this type of material are in actuators and sensors. A typical characteristic property of an EAP is that they will undergo deformation while sustaining forces. For example, EPDM rubber containing various additives for optimum conductivity, flexibility and ease of fabrication can be used as a sensor 12 material for measuring electrode impedance measured on human skin of the wearer. Further, EAPs may be used to measure ECG as well as measuring deformation (i.e. expansion of the waist and therefore breathing can be inferred from EAPs). ECG can be measured using surface electrodes, textile or polymer, as desired.

These electrodes 12 can be capable of recording biopotential signals such as ECG while for low-amplitude signals such as EEG, as coupled via pathways 30 with an active circuit of the electrical components 15 within the housing 24. The ECG sensors 12 a can be used to collect and transmit signals to the computer processor 1 reflective of the heart rate of the wearer. AS such, it is recognized that the electrodes as sensors 12 can be composed of conductive yarn/fibres (e.g. knitted, woven, embroidery using conductive fibres—e.g. silver wire/threads) of the band 10, as desired.

In terms of bioelectrical impedance, these sensors 12 a,b and their measurements can be used in analysis (BIA) via the processor 16 and memory 18 instructions for estimating body composition, and in particular body fat. In terms of estimating body fat, BIA actually determines the electrical impedance, or opposition to the flow of an electric current through body tissues of the wearer interposed between the sensors 12 (e.g. 12 a,b), which can then be used to estimate total body water (TBW), which can be used to estimate fat-free body mass and, by difference with body weight, body fat.

In terms of strain sensing, these sensors 12 c can be operated as a strain gauge to take advantage of the physical property of electrical conductance and its dependence on the conductors geometry. When the electrical conductor 12 c is stretched within the limits of its elasticity such that it does not break or permanently deform, the sensor 12 c will become narrower and longer, changes that increase its electrical resistance end-to-end. Conversely, when the sensor 12 c is compressed such that it does not buckle, the sensor 12 c will broaden and shorten, changes that decrease its electrical resistance end-to-end. From the measured electrical resistance of the strain gauge, via the power 28 that is administered to the sensors 12 via the computer processor 16 acting on stored 18 instructions, the amount of induced stress can be inferred. For example, a strain gauge 12 c arranged as a long, thin conductive fibres in a zig-zag pattern of parallel lines such that a small amount of stress in the direction of the orientation of the parallel lines results in a multiplicatively larger strain measurement over the effective length of the conductor surfaces in the array of conductive lines—and hence a multiplicatively larger change in resistance—than would be observed with a single straight-line conductive wire. In terms of location/structure of the strain gauge 12 c, the strain gauge can be located around the circumference of the band 10. A further embodiment is where the strain gauge 12 c is located in a portion of the circumference, for example in a serpentine arrangement, positioned in a front 52 portion (positioned adjacent to the front of the wearer) of the band 10. The strain gauge 12 c can be configured for sensing in the k Ohm range.

In terms of temperature sensor 12 d, this sensor is used to measure the dynamic body temperature of the wear. For example, the temperature sensor 12 d can be a thermistor type sensor, which is a thermally sensitive resistors whose prime function is to exhibit a large, predictable and precise change in electrical resistance when subjected to a corresponding change in body temperature. Examples cam include Negative Temperature Coefficient (NTC) thermistors exhibiting a decrease in electrical resistance when subjected to an increase in body temperature and Positive Temperature Coefficient (PTC) thermistors exhibiting an increase in electrical resistance when subjected to an increase in body temperature. Other temperature sensor types can include thermocouples, resistance thermometers and/or silicon bandgap temperature sensors as desired. It is also recognized that the sensors 12 can include haptic feedback sensors that can be actuated via the computer processor 16 in response to sensed data 44 processed onboard by the processor 16 and/or instructions received from a third party device 60 or the wearer (operator of the computer device 40) via an interface 20. Another example of temperature sensors 12 d is where thermocouples could be knitted into the band 10 fabric using textile and coupled directly to the body of the wearer through close proximity/contact in order to get more accurate temperature readings.

Sensed Data and Processing

Referring again to FIGS. 2 and 3, the processor 16 (acting on stored 18 instructions) can transmit the collected data 44 (in raw format and/or in preprocessed format from the sensors 12) to an external computer device 40 (e.g. smartphone or other desktop application) for viewing and/or further processing of the sense data. For example, the device 40 application can display the sensed data 44 in a dashboard type format 46 on a display 42 (or other type of GUI interface) for viewing by the wearer (or by another person other than the wearer that has been provided access to the data 44). For example, the sensed data 44 can be provided in a dashboard format indicating real-time (or other selected dynamic periodic frequency) of: body temperature for indicating fluctuations in skin temperature; gyroscope/accelerometer measurements for indicating amount/degree of physical activity (i.e. via sensed motion) of the wearer as well as contributing via gyroscope readings of wearer posture (for example in the case where the band 10 is positioned at the waist of the wearer) as well as determined calculation of number of calories expended; strain gauge measurements (e.g. via conductive yarn) in order to indicate real-time breathing of the wearer as the band 10 expands and contracts as well as the ability to differentiate strain degree contributing to posture angle (i.e. band and associated strain sensor 12 c with change in length as the posture of the wearer changes due to bending at the waist—in the case of the underwear 11 example of FIG. 2); real-time heart rate measurements based on sensed ECG data using the sensors 12 a; and real-time hydration/body fat measurements based on galvanic sensing using the sensors 12 b (and optionally 12 a as further described below).

It is recognised that multiple sources of sensed data (e.g. temperature sensor 12 d with activity/motion sensors 36 can be used in an algorithm stored in memory 18 to calculate calories expended based on activity combined with body temperature). Other combinations of sensed data types can include combinations such as but not limited to: heart rate with activity data; heart rate with activity data with temperature; activity data with bio impedance data; strain gauge for breathing rate data determination with activity data and heart rate data for determination of exertion levels; etc. It is also realized that combinations of sensor type readings can be used by the computer processor 16 to determine exercise activity type being performed by the wearer, based on computer models of activity type with typical sensor data, for example gradual changes in body posture with detected lower levels of heart rate and breathing could be indicative of a wearer practicing yoga. A further type of multiple sensed data usage can be for accelerometer and gyroscope data, such that both can be used or one can be used and the other discounted during determination of a selected metric of the dashboard 46. For example, in the case of the band 10 being situated at the waist of an overweight person, the “off-vertical” reading of the gyroscope would not be indicative of a bent posture (from the vertical), rather due to the folded waistband due to body composition. As such, the degree of gyroscope readings would be discounted from the calculation of the posture determination.

Referring again to FIG. 1, the location of the sensors 12 a,b are such that they are positioned in pairs on either side of a centerline 50, in order to position an appropriate amount of body mass between the sensors 12 a,b as well as, providing an appropriate conductive path through the body of the wearer (e.g. cross body measurement). It is also recognised that placement of the sensors 12 a,b are preferred in body regions where muscle noise (actions of muscles can introduce signal noise into the adjacent sensors 12) is minimized. As such, the sensors 12 a,b can be positioned in the band 10 in a location for positioning adjacent to the hip and/or the kidney of the wearer in the case where the band 10 is positioned at the waist. It is recognised that positioning the sensors 12 a,b in the band 10 in order to be adjacent to either hip of the wearer, i.e. both sensors 12 a,b of the pair to one side of the centerline 56 of the band 10, would provide for a lower signal amplitude/quality when wearer activity is subdued (e.g. resting) however would also advantageously provide an increases signal quality when the wearer is active (as the presence of utilized muscle mass adjacent to the hip region is minimal as compared to other regions about the waist).

It is also recognised that location of the sensors 12 a,b can be positioned to either side of the centerline 60 running front to back rather than to either side of the centerline 56 running side to side (of the wearer), as the separation distance for the typical wearer is greater side to side rather than front to back (i.e. wider between hips verses between spine and belly button).

Further, one example option for the sensor configuration is a 4-electrode ECG sensor configuration. Cost of such an ECG design can be, a factors however the design could potentially give better signal performance. The theory behind the four sensor ECG design is that the processor 16 can switch between each sensor pair (of the multiple pair ECG sensor configuration) to find the one with the best signal quality and use that one during sensed movement of the wearer.

Referring again to FIG. 3, the processor 16 and associated stored 18 instructions can be used to determine (based on received sensor 12 readings) bio impedance values by utilizing both of the ECG sensors 12 a and the sensors 12 b at the same time. This is advantageous as EGG sensing (using sensors 12 a) cannot occur at the same time as bio impedance sensing (using sensors 12 b), as signal amplitude generated by the sensors 12 b oversaturates the EGG sensors 12 a. As such, it is recognised that the processor 16 cycles between ECG readings and bio impedance readings (i.e. these readings are done sequentially rather than in parallel). As such, the processor instructs power to both the sensors 12 a,b on one side of the centerline 50 as drivers and both the sensors 12 a,b on the other side of the centerline 50 as collectors during taking of bio impedance readings. As such, it is recognised that the positioning of the sensor pair 12 a and the sensor pair 12 b can be symmetrical about the centerline(s) 50,56.

Referring to FIGS. 3 and 4, the computer device 14 can be used to send the sensed data 44 to the off band computer device 40, which can then use its own customized applications 43 to process the sensed data 44 to inform the wearer of their physical/mental state on potential adaptations/changes that can be actively done by the wearer. For example, the application 43 can report sensed data 44 pertaining to a combination of temperature and activity over time as an indicator of the quality of sleep of the wearer. Further, the application 43 can notify the wearer of a determined emotional state of the wearer (e.g. based on a combination of breathing data and activity data—with optional ECG data) as well as continued monitoring of the data combination to inform the wearer whether steps taken by the wearer are positively influencing the determined emotional state. Further, the application 43 can track and report on the degree as well as quality/nature of the wearer's activity, for example based on a combination of strain gauge data and activity data. Further, the application can interact with other external computer networked devices 60 (see FIG. 3) such as but not limited to music systems, heating system, lighting systems, etc in response to a determined mood and/or temperature of the wearer based on a combination of sensed data (e.g. activity, heartrate, etc.).

Referring to FIGS. 5 and 6, shown is an alternative embodiment of the band 10, in exploded view. In particular, the band 10 is composed of a front band portion 60 and a back band portion 62, such that the portion 60 has sensors 12 a,b with communication pathways 30 electrically connecting the sensors 12 a,b to respective connectors 64 (which connect to respective connector portions of the PCB 26 (see FIG. 3), in order to electrically couple the sensors 12 a,b to the network interface 20). The band portion 62 has cutouts 66 in order for the sensors 12 a,b to be received in the cutouts 66 when the band portions 60,62 are assembled with one another (e.g. coupled together for example by stitching via adjacently places surfaces 70), thus providing for surfaces 68 of the sensors 12 a,b to become in contact with the skin of the wearer, as the surface 111 is for contact with the skin. It is recognized that the electrically conductive pathways 30 can be electrically conductive fibres interlaced with electrically insulative fibres comprising the material of the band portion 60.

Referring to FIG. 7, shown is an example side view of one of the sensors 12 a,b, such that the portions 60,62 are assembled and the sensors 12 a,b are received in the cutouts 66 (see FIGS. 5,6). It is important to note that the sensors 12 a,b themselves extend from the skin contact surface 111 by a distance X, thus providing for improved contact with the skin of the wearer. In particular, the sensors 12 a,b can have a conductive portion 72 of the surface 68 (i.e. coupled to the communication pathways 30 extending through backing material 74) as well as the raised backing material 74 to provide for the respective extension of the conductive portion 72 of the sensors 12 a,b from the surface 111. For example, the backing material 74 can be comprised of electrically insulative interlaced fibres interleaved with the textile fibres incorporating the material (i.e. electrically insulative fibres) of the band portion 62.

Referring to FIG. 8, shown is a further embodiment of the band portion 80 showing the strain gauge sensor 12 c woven/knit in a serpentine fashion with other insulative fibres comprising the material of the band portion 60. As such, as shown in FIG. 7, it is recognized that once assembled, the band portion 62 would cover the strain gauge sensor 12 c and thus insulate the skin of the wearer from direct contact with the electrically conductive fibres of the strain sensor 12 c. FIG. 9 shows a further geometrical configuration of the strain sensor 12 c.

Referring to FIGS. 5 to 8, it is recognized that they contain example geometrical layouts of the communication pathways 30 (e.g. traces) and the strain sensor 12 c itself. The shown construction of the sensors 12 a,b,c and band portions 60,62 are advantageous, as the entire pattern (of pathways 30 and sensor(s) 12 c) is actually contained within covering portions 60,62 as one assembled (e.g. interlaced) layer of fabric, however the traces (of pathways 30 and sensor(s) 12 c) are knitting inside the knit pattern and therefore as a consequence of that are insulated, therefore inhibiting any necessity of external insulation (glues, laminates, etc), in order to inhibit undesirably application of electrical charge from the traces to the skin of the wearer. Further, the 3D shape (e.g. extension from the surface 111) of the sensors 12 a,b themselves can improves the sensors 12 a,b contact with the skin and can provide for the collection of biometric data across a variety of skin conditions, dry or wet. 

We claim:
 1. A resilient fabric band providing a sensor platform for a wearer in order to sense a plurality of biometric data, the band comprising: a pair of ECG sensors coupled to an interior, surface of a body of the band, each of the pair of ECG sensors located on either side of a front to back centerline of the body; a pair of bio impedance sensors coupled to the interior surface of the body of the band, each of the pair of bio impedance sensors located on either side of the front to back centerline; a strain gauge sensor coupled to the body of the band; a computer device mounted on the body of the band via a housing, the computer device including a power source, a computer processor, a memory for storing instructions for execution by the computer processor, and a network interface for transmitting data sensed by the sensors; and a plurality of communication pathways connecting the computer device to each of the sensors, the communication pathway for sending power from the power supply to the sensors as controlled by the computer processor and for receiving sensed data from the sensors by the computer processor.
 2. The band of claim 1 further comprising a temperature sensor mounted in or external to the housing and facing the interior surface of the body.
 3. The band of claim 1 further comprising the band incorporate as a component of an article of clothing.
 4. The band of claim 3, wherein the article of clothing is underwear and the band is positioned at a waist of the underwear.
 5. The band of claim 1 further comprising motion sensors selected from the group consisting of accelerometer and gyroscope.
 6. The band of claim 1, wherein the strain gauge sensor is interlaced into fabric of the body of the band as a plurality of conductive fibres.
 7. The band of claim 1, wherein the both the bio impedance sensors and the ECG sensors are positioned on one side of a side to side centerline of the body.
 8. The band of claim 1, wherein the communication pathways are conductive fibres interlaced in the fabric of the body of the band. 